The opposition is also reported to have won an overwhelming majority in parliament.

"We shall start as leaders by showing our wealth, and as soon as parliament reconvenes we shall bring and pass the law which shall establish the anti-corruption authority," Mr Kibaki told cheering supporters on Sunday.

Moi is the only president many Kenyans have known

Senior Narc politician Raila Odinga said: "The strong and common will of the people today has brought about a change for which we have toiled long days and nights."

Correspondents say voters appear to have tired of the corruption, poverty and ailing economy that have blighted the lives of many Kenyans over recent years.

The majority can only remember one president - Mr Moi, who has been in power since 1978 but was constitutionally obliged to step down - and this election was eagerly awaited as an opportunity for far-reaching change.

Well-wishing

The international community welcomed Mr Kibaki's victory.

US Secretary of State Colin Powell said: "The president-elect has made a commitment to ending corruption.

Street parties began in Mombasa as soon as unofficial results started arriving

"This would be good for the Kenyan people and,
of course, good for relations with the United States."

South Africa - which currently chairs the African Union - commended "the outgoing President Daniel arap Moi, the government, the political parties and the people of Kenya on the peaceful nature of the election".

Neighbouring Uganda and Tanzania congratulated the Kenyan people.

German Foreign Minister Joschka Fischer described the outcome as a great step forward for democracy in the country.

Kenya's former colonial ruler, Britain, said it looked forward to working closely with Kenya's new government and leader.